In the field of sanitary washing apparatuses that wash the local areas of human bodies, apparatuses having various functions have been devised in order to avoid discomfort of human bodies, including, for example, heater apparatuses that adjust the washing water to proper temperatures, toilet seat apparatuses that properly adjust the temperature of the area where the human body contacts, and so on. Among them, a toilet seat apparatus as mentioned above allows the user to sit on the toilet seat without feeling discomfort even when temperature is low, as in winter (for example, see Patent Document 1).
In the sanitary washing apparatus of Patent Document 1, a linear heater is provided in a toilet seat casing made of magnesium alloy. The linear heater is composed of a core wire, a heating wire wound around the core wire, and a coating tube that coats the core wire and heating wire. The linear heater is arranged in a serpentine manner all over the back surface of the toilet seat casing, and power-supply circuitry is connected to both ends of the heating wire.
In such a structure, a voltage is applied from the power-supply circuitry to the heating wire to cause the heating wire to generate heat. Then, the heat is conducted to the toilet seat casing through the coating tube. Thus, the temperature of the toilet seat casing rises and the user can sit on the toilet seat comfortably.    [Patent Document 1] JP 2003-310485 A